#include <51func.h>
void *threadFunc(void *arg){
    // void * --> long
    long val = (long )arg;
    printf("child val = %ld\n", val);
    ++val;
}
int main(int argc, char *argv[])
{
    long val = 1000;
    pthread_t tid;
    pthread_create(&tid,NULL,threadFunc,(void *)val); // long -> void *
    sleep(1);
    printf("main val = %ld\n", val);
    return 0;
}

